A Langevin type ultrasonic transducer having a configuration in which a stack unit of piezoelectric elements that are integrally sintered is fitted into a recess formed in a metal-made vibration block has been proposed (for example, see Japanese Patent No. 3,914,050).
In the ultrasonic transducer disclosed in Japanese Patent No. 3,914,050, a screw hole (female thread) is formed in the inner wall of the recess of the vibration block, and a bolt is fastened to the screw hole, whereby the stack unit of piezoelectric elements is fixed to the vibration block.
Furthermore, a handpiece for surgical operation incorporating an ultrasonic transducer having a structure in which, for example, a stack type piezoelectric member housed in a recess of a housing is fastened by a horn on which a male thread is formed is known (for example, see JP-A-2004-160081).